21555121044112 has 20 divisors (see below), whose sum is σ = 41763146323500. Its totient is φ = 10777534896128.

The previous prime is 21555121044097. The next prime is 21555121044151. The reversal of 21555121044112 is 21144012155512.

It can be written as a sum of positive squares in 2 ways, for example, as 16493053034896 + 5062068009216 = 4061164^2 + 2249904^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6615264 + ... + 9320512.

It is an arithmetic number, because the mean of its divisors is an integer number (2088157316175).

Almost surely, 2^{21555121044112} is an apocalyptic number.

It is an amenable number.

21555121044112 is a deficient number, since it is larger than the sum of its proper divisors (20208025279388).

21555121044112 is a wasteful number, since it uses less digits than its factorization.

21555121044112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3203250 (or 3203244 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 34.

Adding to 21555121044112 its reverse (21144012155512), we get a palindrome (42699133199624).

The spelling of 21555121044112 in words is "twenty-one trillion, five hundred fifty-five billion, one hundred twenty-one million, forty-four thousand, one hundred twelve".